TGA studies on the combustion characteristics of bituminous coal blends

The combustion characteristics of Chinese bituminous coal blends, which are composed of Ximeng coal with high heating value, high volatile matter and low ash contents and Chengde coal with low heating value, low volatile matter and high ash contents, were studied on a thermogravimetric analyzer (t.g.a.). It is found that the combustion properties of coal blends are strongly influenced by their blend ratios. When the blend ratio of Ximeng coal increases from 10% to 90%, the ignition temperatures of coal blends gradually drop from 465degreesC to 407degreesC and the maximum reaction rates gradually increase from 0.1164 mg/min to 0.2152mg/min. The burnout efficiencies of fixed carbons in the five coal blends are in the range of 73.59%-77.51%, which are apparently higher than that of 71.02% of Ximeng coal and that of 61.16% of Chengde coal.